Sewage flow is one aspect completely ignored as a causative factor in spread of COVID-19. Yet, it could become a potential threat if enough precautions are not taken.
So far, all measures to contain the spread are focussed on contact tracing and containment, with the knowledge that the disease spreads only through droplets.
However, a few studies have said, and the World Health Organisation (WHO) too, has in principle admitted that coronavirus may be present in stool samples of COVID patients.
Though there is no evidence as of now for its transmission from sewage flow, precautions are being spelled out about such possibility.
A document by the Indian Society of Heating, Refrigerating & Air Conditioning Engineers has asked toilet users to be wary of the airborne droplet residue while flushing. WHO has confirmed that airborne transmission may be possible in specific circumstances and settings.
If any outbreak is to happen through sewage flow, Hyderabad with its poorly managed system has high potential for disease flare up.
The Telangana State Pollution Control Board (TSPCB) has already advised healthcare facilities and agencies operating the Sewage Treatment Plants to disinfect the treated waste water to deactivate coronavirus.
Unfortunately, it is a fact that the installed capacity of STPs is only about 50 per cent of the city’s sewage, that is 700 million litres per day (MLD), while the total sewage generated is about 1500 MLD. The untreated sewage goes directly into Musi River, which could endanger the lives of hundreds of slum dwellers living along the river banks.
Though as per norms, the treated water should be disinfected prior to letting into water bodies, with the Hyderabad Metropolitan Water Supply and Sewerage Board (HMWS&SB) outsourcing the maintenance of STPs to private agencies, adherence to the disinfection norms could be dicey.
Though officials confirm that the treated water is mixed either with Chlorine or Sodium hypochlorite before release, sources say that the disinfection should be continuous procedure, and how adherent the agencies are during night cannot be confirmed.
Besides, poor maintenance plagues the 27 I&D (Interception & Diversion) units across the city, installed to divert sewage from nalas into mains, sources say. Quite a few need pumping as against gravity for flow, and effectiveness of the pumps is uncertain, they say.
Several and frequent leakages in the aged pipelines too could prove dangerous. The major COVID-19 healthcare facility Gandhi Hospital does not have its own STP, and all the outflows from the hospital are treated at Amberpet STP. Any leakages on the way should be monitored strictly and repaired, say experts.
“Maintenance and sample collection of treated water at STPs should be monitored stringently, and proper functioning of the I&D units should be ensured. Coronavirus is known to stay in faecal flows for 48 hours. Hence adequate precautions should be taken,” said chairman of the Institution of Engineers and former director (Operations) HMWS&SB G. Rameshwar Rao.
